When federal agents raided a San Rafael apartment complex in the early morning hours of March 6, 2007, searching for 30 undocumented immigrants, they left behind a lot of terrified children, Kathryn Gibney, the principal at nearby San Pedro Elementary School, said.

The agents shone flashlights in the children's faces. Several parents were handcuffed in front of their kids. The next day 40 of the school's 400 students were too frightened to show up for class, and others arrived in tears. A year later, Gibney said the effects continue with higher absenteeism, lower test scores and increased counseling for her students.

"They left behind them a trail of fear," Gibney told lawmakers Tuesday in a hearing before a House Education and Labor subcommittee.

Petaluma Democratic Rep. Lynn Woolsey called the hearing in response to growing anxiety among immigrants and the schools, churches and social service agencies that serve them, that stepped-up raids by the Department of Homeland Security's Immigration and Customs Enforcement (ICE) agency are coming at a high cost to children. Woolsey said she is considering legislation that would require the agency to follow guidelines to protect children.

Earlier this month, the Oakland Unified School District sent uniformed officers into an elementary school in East Oakland to reassure parents and students after reports of ICE vans in the area. The agency insisted it was not targeting the school, but seeking adults in the area who had been named in arrest warrants.

Child required to translate

Gibney cited another incident on May 8 when federal agents stopped a father walking his daughter to Bahia Vista Elementary School in San Rafael. Since the agents could not communicate with the father, the second-grader had to serve as a translator. The father, who was undocumented, was arrested.

The arrests are part of a nationwide crackdown on undocumented immigrants - first dubbed "Operation Return to Sender" in 2006 - that targets people who ignore deportation orders. Since October, the agency has apprehended more than 19,000 people nationwide, including 1,620 in Northern California.

Virginia Kice, an ICE spokeswoman in California, said people often mistakenly believe federal agents target schools or churches, which she said they virtually never do. Almost all the arrests occur at home.

"We do that because our goal is officer safety and the safety of people we interact with," Kice said. "I don't know of any situation where we have targeted a school."

But lawmakers at Tuesday's hearing said they fear the impacts on children even if the arrests occur away from schools. About 4.7 million children in the United States have at least one parent who is undocumented; two-thirds of those kids were born in the United States and are citizens, according to federal figures.

Children swept up

Woolsey said children are often getting swept up in the arrests. She pointed to the case of Kebin Reyes, who was 6 when his father was apprehended during the March 2007 raid in San Rafael. Reyes, whose father is his sole parent in the United States, was detained for 10 hours in an ICE field office when his father was arrested. (The American Civil Liberties Union and the San Francisco Lawyers' Committee for Civil Rights is now suing the agency, alleging that it violated Kebin's constitutional rights.) Kebin is a citizen, but his father is not.

Woolsey said after a raid this month at the Agriprocessors Inc. meat processing plant in Postville, Iowa - the largest workplace raid in U.S. history, which netted 389 arrests - a nun at a local Catholic church told the committee that many children were sleeping in the pews, fearing more raids.

"She said that most of these children are not going to school," Woolsey said. "They are traumatized and fearful."

James Spero, the deputy assistant director of ICE's Office of Investigations, told lawmakers the agency tries to carry out the raids in a humane way. He noted that after the Postville raid, 62 of those arrested were given a conditional release for "humanitarian purposes" - in most cases because they were the sole caregiver to children.

But other officials criticized the agency for failing to alert state and local authorities when they carry out raids. Simon Romo, chief counsel of New Mexico Child Protective Services, said he believes the raids are causing severe trauma for children when their parents are suddenly pulled out of their lives.

"Children need to see their parents," Romo testified. "The fact that they are told they are OK is insufficient. ... When you remove a parent from the life of a child, you leave them wondering. You set off these bombs that will go off throughout the rest of their development."

Republicans back ICE

But some Republicans rallied to the defense of the agency, saying ICE officials should not be blamed for the consequences of enforcing the law.

"A person who entered the country illegally or overstays their visa - they are the ones who are really putting those children in jeopardy by their own actions, and they should take those children into account," said Rep. Buck McKeon, R-Santa Clarita (Los Angeles County).

Janet Murguia, president of the National Council of La Raza, a Latino civil rights group, said lawmakers should focus on crafting a more humane immigration policy that focuses on protecting children and keeping families united while still enforcing the law.

"I don't think anyone is suggesting we should punish these kids for the actions of their parents," she said. "We're not looking at whether we enforce these laws, but how we enforce these laws."